ByKathleen McLaughlin, CorrespondentMay 6, 2014

In this photo taken by a mobile phone, a suspected assailant is taken away after being subdued in an attack at a railway station in Guangzhou in south China's Guangdong province Tuesday, May 6, 2014. Six people were stabbed today in the knife attack at Guangzhou station in southern China, according to official media.

Beijing — China is once again scrambling for answers in the wake of another ferocious train station attack, the third in as many months.

Six people were stabbed today in the knife attack at Guangzhou station in southern China, according to official media. Police said they shot and injured one male assailant, but eyewitnesses told Chinese media there were at least two knife-wielding attackers and possibly more. The one suspect is reportedly hospitalized in Guangzhou, the capital of Guangdong Province, a manufacturing hub that is a magnet for migrants from across China.

Suspicion for the attack has fallen on Uighurs, a Muslim Turkic ethnic group from the far west province of Xinjiang. Witnesses told Chinese media the assailants were wearing “small white hats,” which could indicate they were part of a Muslim minority. White skullcaps are commonly worn by Uighurs and other Muslims in Xinjiang and other parts of China.

Last week, a bombing killed three and injured 79 people at a train station in Urumqi, the Xinjiang capital. Two assailants were among the dead. President Xi Jinping, who was in the city at the time of the attack, pledged to stamp out terrorism with “decisive action.” Police said they are searching for a Uighur man in connection with that attack, but information remains sparse about both motives and suspects.

In March, a gang of eight knife-wielding attackers killed 29 people and injured 143 others at a train station in the southwestern city of Kunming. Police, who called the incident a terrorist attack perpetrated by Uighur separatists, shot four of the perpetrators. Witnesses reported a frenzied slashing attack that came without warning.

More remains unknown than known about these attacks, however, largely thanks to China’s heavy hand in censoring its own media and controlling access to Xinjiang by foreign media. Though the province is technically open to journalists, reporters are heavily monitored there and sometimes sent packing as soon as they arrive. Local sources are watched and can be punished for speaking out.

Meanwhile, in comments likely to provoke the Chinese government, exiled Uighur activist Rebiya Kadeer has urged authorities to look into the cause of Xinjiang's turmoil. China has in the past blamed Uighur unrest on outside forces stirring up dissent and is particularly fond of lambasting Ms. Kadeer, who heads the World Uyghur Congress.

“I also call on the Chinese government to take complete responsibility for the failure of its ruthless policies, which is what led to this tragic outcome,” she told Radio Free Asia. “I ask the international community to look deep into the root causes which provoked this incident…. I call upon the international community to conduct a fact-finding investigation into this event.”

Uighurs have long complained of religious and cultural repression by the Chinese government. No organized group has claimed responsibility for this year's terror attacks or a suicide car bombing last year in Beijing's Tiananmen Square.